Fatty acids are composed of a carboxyl group and a hydrocarbon chain. Individual fatty acids are distinguished from one another by the nature of the hydrocarbon chain. This chain can vary in length from 4 to 24 carbon atoms and can be saturated, monounsaturated (one double bond, MUFA) or polyunsaturated (two or more double bonds, PUFA). The most common fatty acids in edible oils and fats are those containing 18 carbons. These include: stearic acid (a saturated fatty acid), oleic acid (a monounsaturated fatty acid), and linoleic and linolenic acids (polyunsaturated fatty acids containing two and three double bonds, respectively). The configuration of octadecanoic fatty acids is as follows:
FormulaCommon NameAbbreviationStearic18:0 Oleic18:1 n-9 cis Linoleic18:2 n-6 cis Linolenic18:3 n-3 cis Elaidic18:1 n-9 trans
Fatty acid abbreviations are made according to the number of carbon atoms in the molecule and the number of cis ethylenic double bonds. The general assumption is that all multiple double bonds are methylene-interrupted. The chemical nomenclature requires that carbon atoms be counted from the carboxyl end of the fatty acid. However, for biological activity carbon atoms are numbered from the terminal methyl group to the first carbon of the ethylenic bond. Such a classification is designated by the symbol                 ω-x,        
 ω-x, or n-x, nx, where x denotes the position of the double bond closest to the terminal methyl group. For example, linoleic acid with two double bonds, where one is located on the sixth carbon atom counted from the methyl group, will be abbreviated as C18:2n-6.
In the case of unsaturated fatty acids, the carbon chain is bent into a fixed position at the double bond, resulting in several possible geometric isomers. When the portions of the chain are bent towards each other they are called cis; and when bent away from each other, trans. The natural configuration of fatty acids is cis, as shown for oleic acid. The corresponding trans configuration, elaidic acid, results in a straight chain.
Currently in the U.S., partially hydrogenated fats are employed in the production of many chemically leavened and yeast-raised bakery products (e.g., cakes, crackers, cookies, cereal bars, etc.). The partial hydrogenation of domestic oils originating from soybean, cottonseed, corn, sunflower, and/or canola allow the chemical reduction of the unsaturated fatty acids to saturated fatty acids which provide greater oxidative stability.
Hydrogenation is a physical modification of these liquid oils, imparting thereto a solid fat content and an increased melting point, as saturated fatty acids are solid at room temperature whereas unsaturated fatty acids are liquid at room temperature As a result, the oils which are naturally liquid can be transformed into a semi-solid fat with a particular melting profile. To provide maximum eating pleasure with this form of the fats, the hydrogenation process of these fats is highly controlled and allowed to proceed only partially, that is, to allow only some of the unsaturated fatty acids and/or bonds thereof to be reduced to the saturated form. These types of fats and fatty acids are called “partially hydrogenated fats” or “partially hydrogenated oils” or “partially hydrogenated fatty acids”.
In addition to the reduction of the unsaturated fatty acids to the saturated form, in partial hydrogenation, a side reaction occurs in which the natural form of the unsaturated bond (referred to as a cis isomer) will twist in the plane, to form what is referred to as a trans isomer of the bond of the of the unsaturated fatty acid.
Generally, cis isomers are those naturally occurring in food fats and oils. Although very small amounts of trans isomers occur in fats from ruminants or can result from the deodorization step in refining of vegetable fats and oils, most trans isomers result from the partial hydrogenation of fats and oils. Also, it is possible for the unsaturated bond to move laterally along the fatty acid chain and this is referred to as a positional isomer. These isomers are formed at the high temperatures (e.g., 180°-240° C.) common during the hydrogenation reaction and when the Nickel catalyst typically employed during the hydrogenation reaction unsuccessfully introduces a hydrogen atom to both sides of the unsaturated bond. These isomers are rather stable and will then remain unless the hydrogenation reaction is continued until there is a complete reduction of the unsaturated fatty acids. Therefore, partially hydrogenated fat will always contain some proportion of these positional and geometrical isomers; and, those isomers, especially those that do not naturally occur in fats, can present problems.
For instance, typically, shortenings employed in bakery products may contain 15-35% trans isomers. The use of these isomers has become more scrutinized by nutritional science in the last several years. There have been clinical studies reporting observed negative health effects correlated to the presence of trans fatty acids formed during the partial hydrogenation of oils, e.g., a positive correlation with coronary heart diseases an increase in the ratio of plasma low density lipoproteins (LDL) to high density lipoproteins (HDL) and thus a possible increase in the risk of coronary heart disease (see, e.g., Elias, B. A., Food Ingredients Europe: Conference proceedings, London, October 1994 (Publisher: Process Press Europe, Maarssen); Willet, W. C. et al., Lancet 341 (8845); 581-585 (1993); Khosla, P. et al., J. Am. Col. of Nutrition, August 1996, 15(4):325-339 (American College of Nutrition, NY, N.Y.)).
However, not all trans fatty acids are necessarily “bad”; and, other, including more recent, studies have shown that trans fatty acids may not have such a correlation with coronary heart disease and/or may be akin to saturated fatty acids, fats or oils. Cf. Clarke et al., “Dietary lipids and blood cholesterol: quantitative meta-analysis of metabolic ward studies” BMJ 1997; 314:112 (11 January) (Forty solid food experiments provided information on dietary intake of trans monounsaturated fats, mainly trans C18:1; elaidate: trans fatty acids account for only 2% of calories in the British diet, so replacing half isocalorically by carbohydrates would be expected to reduce blood total cholesterol by only 0.05 (0.01) mmol/l; however, intake of monounsaturated fat had no significant effect on total or low density lipoprotein cholesterol despite raising high density lipoprotein cholesterol by about as much as polyunsaturates; “combined effect of changing the type, but not the amount, of dietary fat by replacement of 10% of dietary calories from saturates by monounsaturates (5%) and by polyunsaturates (5%), together with consuming 200 mg less dietary cholesterol, would be a reduction in blood cholesterol of about 0.8 mmol/l, with the reduction chiefly in low density lipoprotein cholesterol”); Khosla et al. “Replacing Dietary Palmitic Acid with Elaidic Acid (t-C18:1Δ9) Depresses HDL and Increases CETP Activity in Cebus Monkeys,” The Journal of Nutrition Vol. 127 No. 3 March 1997, pp. 531S-536S (palmitic acid- and elaidic acid-rich diets produced identical effects on LDL metabolism in normocholesterolemic cebus monkeys fed diets with low levels of cholesterol); McMillan et al. “Elaidinized olive oil and cholesterol atherosclerosis,” B. I. Arch. Pathol. 76:106-12 (1963) (in rabbits trans fatty acids have been shown to raise cholesterol levels but do not increase the severity of atherosclerosis); van de Vijver et al. “Trans unsaturated fatty acids in plasma phospholipids and coronary heart disease: a case-control study,” Atherosclerosis 1996 Sep. 27; 126(1):155-61 (no significant correlations were found between percentages of trans fatty acids in plasma phospholipids and plasma LDL or HDL cholesterol levels; findings do not support an association between trans fatty acid intake and risk for coronary heart disease); van de Vijver et al. “Association between trans fatty acid intake and cardiovascular risk factors in Europe: the TRANSFAIR study,” Eur J Clin Nutr 2000 Feburary; 54(2):126-35 (while high intakes of trans fatty acids (TFA) have been asserted by others to exert an undesirable effect on serum lipid profiles, no associations were found between total TFA intake and LDL, HDL or LDL/HDL ratio after adjustment for cardiovascular risk factors; additional adjustment for other fatty acid clusters resulted in a significant inverse trend between total TFA intake and total cholesterol (Ptrend<0.03)—the most abundantly occurring TFA isomer, C18:1t, contributed substantially to this inverse association; and, at the current European intake levels of trans fatty acids they are not associated with an unfavorable serum lipid profile).
Furthermore, it is important to note that the majority of trans isomers formed during partial hydrogenation of vegetable oils and fats are in different positions along the fatty-acid backbone (primarily elaidic) than those that occur naturally in animal fats (vaccenic) and that fats from ruminants reportedly account for 20% to 25% of TFA (trans fatty acid) intake. Thus, trans fats from animal and vegetable sources may present different associations with risk factors for heart disease. Indeed, since the trans form of fats may provide many of the same properties as saturates, it has been commonly referred to as the stealth fat.
Accordingly, as there seems to be reports weighing in on both sides of the “trans fat issue”, and the source of the trans fat—animal vs. vegetable—may impact upon risk factors, there may there may be a problem in the art in the use of large or significant amounts of partially hydrogenated fats and oils in food products; and, the American Heart Association recommends using naturally occurring unhydrogenated oil when possible.
Moreover, the problems presented by partially hydrogenated fats or oils cannot be addressed by merely employing naturally saturated fats or oils; and, the use of naturally saturated fats and oils present problems.
For instance, as many nutritionists caution against replacing TFAs in the diet with saturates, especially palmitic acid, it is now not recommended to substitute trans fats and oils with saturated fats and oils; and, the substitution may result in little biological significance (see literature cited supra). Indeed, saturated fatty acids may cause greater health issues than TFAs as saturated fatty acids (i.e. palmitic acid) may raise total cholesterol mostly due to an increase in low-density lipoprotein (LDL) cholesterol from saturated fatty acids.
Another possible replacement for partially hydrogenated fats or oils is interesterified fats that may be engineered from fully refined liquid oils and fully hydrogenated fats. These engineered interesterified fats are from a process wherein the fatty acids on the triglycerides of two fats are randomized via a chemical catalyst or enzyme, resulting in a triglyceride composition that can provide a suitable melting profile. Ideally, the selection of oils for this process may include a non-hydrogenated oil and either a tropical fat (such as coconut oil, palm kernel oil, and/or palm oil or fractions thereof), which is naturally high in saturates, or a fully hydrogenated fat, which is fully saturated and without TFAs. The ratio of the oils and fats may be selected to mimic properties of partially hydrogenated fats. In addition, these engineered fats can be processed to conserve TFAs. However, an unfortunate shortcoming of engineered fats may be the potential increase in saturated fat depending on its application. In addition, a food manufacturer or processor would be required to declare the fully hydrogenated or tropical fat on its product label, which may be unfavorable to a consumer as these fats are associated with the formation of TFAs and/or with high saturates content.
Polyunsaturated fatty acids are considered a highly essential component of a healthy diet according to the U.S. Food and Nutritional Board's Recommended Dietary Allowances (tenth ed. 1989) (e.g., amount of dietary linoleic acid for humans should be a minimum of 2% of dietary calories and preferably 3%; and, the requirement for linolenic acid has been estimated to be 0.54% of calories)
While it would be desirable to replace partially hydrogenated fats simply with natural vegetable oils since natural vegetable oils have a relatively high ratio of polyunsaturated to saturated fatty acids, attempts to do this so far have also proven to be quite unsatisfactory in regard to either the processing or organoleptic (e.g., taste, texture, eating) aspects of the food product. For example, there may be insufficient oil retainment in the dough or batter resulting in separation of oil. Or, the liquid oil may render the dough or the like sticky or long in texture preventing the required sheeting, cutting, molding, or extrusion during processing. Further, oils may depart from the food product too quickly in the mouth, imparting an off-taste and off-feel to the product as it is being consumed.
Another related problem in the preparation of food products is “bloom”; a phenomenon wherein certain fats or oils permeate to the surface of a food product, such as a cookie, and leave a scoring on the surface of the food product. This “bloom” renders the food product not visually appealing and ergo not consumable. It would be desirable to provide a shortening system which does not suffer from “bloom.”
In the production of food surfactants or emulsifiers, a triglyceride may be reacted with glycerol and to form a mixture of mono- and diglycerides. Thus, the products from this reaction is typically subjected to a treatment to isolate a monoglycerides product from a diglycerides and triglycerides product; the diglycerides and triglycerides product is considered a by-product of the reaction of a triglyceride with a glycerol to obtain monoglycerides for surfactants or emulsifiers. The diglycerides and triglycerides product is sometimes discarded, or recycled back to a reactor wherein the reacting with glycerol is occurring so as to enhance the production of monoglycerides (see, e.g., Lauridsen, “Food Surfactants, Their Structure And Polymorphism” Technical Paper TP 2-1e Danisco Ingredients, Braband Denmark, and references cited therein).
Systems functioning as or containing fats or oils have been proposed (see, e.g., CN 1078353, U.S. Pat. Nos. 5,458,910, 5,612,080, 5,306,514, 5,306,515, 5,306,516, 5,254,356, 5,061,506, 5,215,779, 5,064,670, 5,407,695, 4,865,866, 4,596,714, 4,137,338, 4,226,894, 4,234,606, 4,335,157, 3,914,452, 3,623,888, DE 291240A). In addition, reference is made to U.S. Pat. No. 5,908,655 and EP1057887A1, and documents cited therein including, U.S. Pat. Nos. 2,132,437, 2,442,534, 3,943,259, 4,018,806, 4,055,679, 4,154,749, 4,263,216, 4,366,181, 4,386,111, 4,425,371, 4,501,764, 4,510,167, 4,567,056, 4,596,714, 4,656,045, 4,732,767, 4,889,740, 4,961,951, 5,110,509, 5,211,981, 5,316,927, 5,434,280, 5,439,700, 5,458,910, 5,470,598, 5,589,216, 5,612,080, 5,718,938, and 5,756,143; and, Feuge et al., Modification of Vegetable Oils VI: The Practical Preparation of Mono and Diglycerides, Oil and Soap, 23 (259-264), 1946; Handbook of Food Additives, 2nd Edition, vol. 1, Chapter 9, Surface Active Agents, pp. 397-429; Bailey's Industrial Oil and Fat Products, 4th Edition, vol. 2, Chapter 4, pp. 130-147; and Krog, “Interactions of Surface-Active Lipids with Water, Protein and Starch Components in Food Systems,” Technical Paper TP 3-1e , Danisco Ingredients, Braband, Denmark.
However, these systems have not sufficiently addressed the problems in the art; and, these systems have not been reported to provide the synergistic, and surprisingly superior properties for processability, including improvement in organoleptic properties of foodstuff, of the present invention. Further, these systems may not sufficiently address new or additional issues that have arisen in the art.
More in particular, partially hydrogenated (PH) fats are used in bakery and bakery related food used as shortenings, such as dough fat or filling fat. These fats may provide specific functional characteristics to a food product, such as aeration properties, emulsification properties, lubrication, organoleptic properties, structural stability, and increased shelf life.
For example, PH fats may serve to lubricate the dough or the like to provide good organoleptic properties. That is, PH fats are utilized to help shorten the texture of a food product to enhance the palatability of the baked item. Further, PH fat serves to lubricate dough or the like to provide necessary shortness during processing resulting in an even distribution of fermentation gasses so that the food products exhibits less deformities and imperfections.
Also, PH fats aid in the development or in the stability of the food product structure during production or in the finished good for a variety of baked goods, including cakes, extruded and sheeted baked goods, molded, or machine deposited (wire cut) cookies.
These functional characteristics may be limited by the type of shortening (i.e. solid fat index, the presence of emulsifiers), the level of shortening, and the manner in which it is added, for example, how well the fat is dispersed or applied.
In addition, emulsifiers have been utilized in bakery related items such as cookies, cakes, and other chemically leavened fine bakery items for quite some time. For example, mono- and diglycerides and lecithin have utilized in bakery shortenings to facilitate creaming and to increase the shortening effect, i.e. to spread fat to a further degree. Also, such emulsifiers have been utilized in partially hydrogenated bakery fats to enhance lubrication. As a further example, emulsifiers, such as mono- and diglycerides, propylene glycol esters of fatty acids, lactic acid esters, polysorbates, and sorbitan esters, have been utilized to strengthen cake batter during preparation for aiding in aeration. By strengthening the batter, the final cake will have a finer cell structure resulting in better organoleptic properties and better overall appearance.
New labeling requirements (“nutritional panel issues”) for trans fats have been proposed and as a result manufacturers will attempt to conserve or reduce the level of trans by replacing the current partially hydrogenated fats with options such as: (1) Blend of fully refined oils with fully hydrogenated fats; (2) Interesterification of fully refined oils with fully hydrogenated oil and/or tropical fats or tropical fat fractions; and (3) Blends of domestic oils with tropical fats and or tropical fat fractions.
Disadvantages for these options would include possible functional problems or marketing issues.
For example, in options (1) or (2), the declaration of hydrogenated fats would be a marketing problem due to the association of trans fatty acids with hydrogenation. In addition, from a functional point of view, option (1) would provide high melting solids which may result in waxiness and/or dryness in the mouth, leading to poor flavor release. Further, for options (2) and (3), the declaration of a fully hydrogenated oil and/or tropical fats would be a marketing problem due to the association of saturated fats and tropic fats.
Thus, for instance, U.S. Pat. No. 5,908,655 and EP1057887A1 provide a shortening system. The shortening system comprises an admixture of at least one non-hydrogenated vegetable oil and at least one isolated stearine fraction obtainable from glycerolysis/interesterification of a fat or oil, wherein the isolated stearine fraction has an enhanced concentration of diglycerides.
In these documents, the monoglyceride of the shortening system is one which is normally solid at room temperature, or one which is a stearine fraction, or one that is with a diglyceride and is a stearine fraction or normally solid at room temperature, e.g, monoglycerides and diglycerides derived from fats and oils such as palm stearine that are high in saturated fatty acids. The marketing issue of the association of saturated fats and tropic fats is not addressed in these documents.
It would be advantageous and an advance in the art to provide a shortening system, such as dough fat or filling fat, that addresses issues in the art and is useful for the production and stabilization of bakery related products, such as cookies, crackers, and assorted baked goods which are sheeted, extruded, and/or laminated.